1. Technical Field
Novel photoresist monomers, polymers thereof and photoresist compositions containing the same are it disclosed. In particular, photoresist polymers suitable for a photolithography process using DUV (deep ultraviolet) light source, such as VUV (157 nm) in fabricating a minute circuit for a highly integrated semiconductor device, photoresist compositions containing the same, and preparation process therefore are disclosed.
2. Description of the Related Art
A photoresist for an ArF and VUV (vacuum ultraviolet) should have low absorbency of 193 nm and 157 nm wavelengths, excellent etching resistance and adhesiveness on a substrate, and development ability in a commercially available developing solution, such as aqueous tetramethylammonium hydroxide (TMAH) solutions of 2.38 wt % or 2.6 wt %.
Much research has been conducted on resins having a high transparency at 193 nm and etching resistance similar to Novolac resins. However, most of the resists are not suitable resist for VUV due to their high absorbency at 157 nm wavelength. Also, research has been conducted on photoresists containing fluorine and silicon to solve the above problem. However, most polyethylene, polystyrene or polyacrylate polymers containing fluorine have weak etching resistance, low solubility in commercially available aqueous TMAH solutions and poor adhesiveness to the silicon wafer. In addition, these photoresists are difficult to mass-produce and are expensive.